Question: What is the had reason of revolutions of 1917-1923 between central powers?
Paraphrase: What was the reason for the 1917.1923 revolutions between central powers?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q7318933 wdt:P828 ?answer . ?answer wdt:P710 wd:Q152283}
Answer: World War I